If I wanted to replace the Westlake tires that came with our Redwood; 215/75r?17.5 with Goodyear or Sailun would I need to replace the wheel as well? I think the OEM wheel is 6" and from what I've read the Goodyears need 6.5".

If I wanted to replace the Westlake tires that came with our Redwood; 215/75r?17.5 with Goodyear or Sailun would I need to replace the wheel as well? I think the OEM wheel is 6" and from what I've read the Goodyears need 6.5".

I would say NO, can't see what difference a 1/2" would make.
I think you'll find the Sailuns to be MUCH cheaper than the GYs & in my opinion just as good a tire.

If I wanted to replace the Westlake tires that came with our Redwood; 215/75r?17.5 with Goodyear or Sailun would I need to replace the wheel as well? I think the OEM wheel is 6" and from what I've read the Goodyears need 6.5".

If I understand you correctly your redwood currently has 235/80 or 85R16 load range G tires correct?

You cant mount a 17.5" tire on a 16" wheel, that would be very hazardous to your health!

Many of us have gone to aftermarket 17.5" wheel and tire combo because they can hold 4950 lbs or more depending on the size and load rateing of the tires you decide to use. Some tire and wheels combos are not suited to be used togeather . For example many load range E 16" wheels are only rated at 80 psi max but you can safely mount a load range G tire on it but you could NOT inflate it to the maximum side wall recommended 110 psi because the wheel wasn't rated for that high of air pressure. so you need to know the weight and PSI rating on your current wheels if your just doing a tire upgrade. for a compleat wheel a tire combo you have some options that don't drain your bank account. Sailun tires are reasonable priced and seam to have a good reputation for not exploding . I am running the S637 Sailun on Alcoa wheels

EDIT: just notice you have a 2018 , those came stock with 17.5" wheels ! as long as you don't go to a wider tire profile your fine with any brand tire.

To be honest, I think my 2014 Redwood 36RL with the Goodyear G614 option came from the factory with G614s on 6" wheels. (back then you could order G614s and you got 5 of them )

A note on pressure - I got in a case with the NHTSA against a wheel manufacturer where they were relabeling maximum pressure on a wheel without testing the wheel to accommodate a manufacturer. As it turns out, there really is no pressure test performed on alloy wheels, or load test. Load ratings are based on a specification of the alloy and also dictate stud size, number and pattern size. I always thought these wheels were rigorously tested, but they actually aren't tested at all. There were probably some baseline tests years ago and now they just computer model after those. Alcoa may be the exception as a US company. The NHTSA explained to me that the pressure on the wheel has more to do with the tire they are designed to accept and the stem, and nothing to do with the strength of the wheel. The alloy itself could hold far more pressure than that.

If you check out tredittire.com, they no longer provide a pressure on their wheel ratings, only load.